The perception of time is influenced by a variety of non-temporal factors. Previous studies have suggested that time may be altered by relational differences in size, numerical quantity, brightness, and speed. These studies have led to the suggestion of a generalized magnitude system in the parietal lobe that processes abstract quantities, with congruency effects across magnitude dimensions. We here turn to an as-yet unexplored dimension in time perception, that of perceived distance. Across three experiments, 60 human participants judged the duration of two visual stimuli, of different sizes, appearing at different spatial locations for a range of sub-second durations. In half of the trials, these stimuli were overlaid on a common scene depicting a city street; crucially, the background context created a relational distance between the two stimuli where one stimulus appeared farther than the other. Our results demonstrated that larger stimuli were judged to be longer in duration when the larger stimulus was perceived as closer (Experiment 1) or farther (Experiment 2); moreover, when both stimuli were the same size, the farther stimulus was judged to be longer in duration (Experiment 3). Curiously, these effects only occurred when the city context was provided; no effect of size on time occurred when a blank background was used, contrary to previous work. These results suggest that larger stimuli are only judged as longer when an appropriate context is provided, and not when the stimuli occur at sufficiently different locations, implying that magnitude judgments are normally computed separately, but interact in particular circumstances. Furthermore, they suggest that when that context includes distance, congruent information influences temporal perception, such that farther, and so relatively larger, stimuli are perceived as longer in duration. These findings suggest a fundamental connection between space and time, and suggest that relational differences are computed on a common scale.